2,796 research outputs found
Topological incidence rings, their groups of units and incidence functors
We focus on working on incidence rings and their group of units. Some general
properties about them are given, including how they are always the inverse
limit of finite matrix groups/rings, giving a natural way to define their
topology. Such construction can also be translated as a functor from the
category of locally finite, preordered sets to the category of topological
rings. It is shown that under some assumptions on the ordered sets, simple
matrix groups over a field can be built from the group of units of such rings.Comment: 35 page
Analysis of the influence of the líbero in different phases of game in volleyball
El objetivo del estudio fue analizar la participación y la influencia del jugador líbero en la fase de ataque y en la fase de defensa en voleibol masculino de alto nivel. La muestra de estudio estuvo compuesta por 1101 acciones de juego de recepción y defensa, de los cuatro equipos masculinos mejor clasificados en los JJOO de Pekin 2008. Las variables consideradas en el estudio fueron: clasificación del equipo, jugador receptor/defensa, zona de recepción/defensa, eficacia de recepción/defensa, eficacia de la colocación, zona de ataque/contraataque, tiempo de ataque/contraataque, eficacia de ataque/contraataque. La medida de dichas variables se realizó mediante la observación sistemática, indirecta y externa. Se recurrió a la estadística descriptiva y, posteriormente, se utilizaron técnicas de estadística inferencial, basada en tablas de contingencia, valores de Chi-cuadrado y V de Cramer. Los resultados mostraron que, en la fase de defensa, hubo asociaciones
significativas entre: el jugador que defiende y la zona de defensa, predominando la defensa del líbero en zona 5; el jugador que defiende y la eficacia de la defensa, siendo mejorada por parte del líbero; el jugador que defiende y la zona de contraataque, incrementándose los ataques por zona 6 cuando defiende el líberoThe aim of the study was to analyse the libero’s participation and their influence in the attack and defence phases in men's elite volleyball. The sample of this study was composed by 1101 pass and defence game actions of the four highest-placed teams in the 2008 Beijing Olympic Games. The study’s variables include team classification, receiving/defending player, pass/defence zone, pass/defence effectiveness, setting effectiveness, attack/counterattack zone, attack/counterattack time, and attack/counterattack effectiveness. These variables were measured by both indirect and external systematic observation. A descriptive statistical study was used, followed by inferential statistical techniques based on contingency tables, Chi-square tests, and Cramer's V values. The results revealed that there were significant associations during the defensive stage of the game between the defending player and the defensive phase, the libero’s defence predominating in zone 5; the defending player and defence efficiency, which is improved by the libero; the defending player and counterattack, as attacks increased in zone 6 when the libero was defendin
UCSD Performance-Based Skills Assessment (UPSA): validation of a Brazilian version in patients with schizophrenia
AbstractThe UCSD Performance-based Skills Assessment (UPSA) is a measure of Functional Capacity and assesses skills involved in community tasks. It has good psychometrics properties, and is currently recommended as a co-primary assessment of cognition in the MATRICS Project. To our knowledge so far, there are no studies in western developing countries concerning Functional Capacity in Schizophrenia. The aims of this study were to translate, culturally adapt and validate the UPSA to assess Functional Capacity in community-dwelling patients with Schizophrenia living in Brazil. Eighty-two subjects (52 patients, 30 controls) were evaluated using: the Brazilian version of the UPSA (UPSA-1-BR), PANSS, Personal and Social Performance (PSP) and Global Assessment of Functioning (GAF). In the reliability test, UPSA-1-BR showed good Internal Consistency (Cronbach’s alpha of 0.88) and strong correlation between test and retest (4-month gap; r = 0.91; p < 0.01). Spearman’s rho values showed a moderate correlation between UPSA-1-BR and both PSP (0.50; p < 0.01) and GAF (0.46; p < 0.01) scores. UPSA-1-BR is capable of differentiating people with and without Schizophrenia. Patients scored lower than controls (58.9 versus 79.1), with an AUC of 0.79 (95%IC: 0.69–0.89). Sensitivity and specificity values of 0.71 and 0.70, respectively, were found in the cut-off point of 73.5, for separation of patients and controls, with predictive values of 80% (positive) and 58% (negative). UPSA-B-BR was also evaluated. UPSA-1-BR and its brief version presented adequate psychometric properties and proved to be valid and reliable instruments in the assessment of Functional Capacity in subjects with Schizophrenia
Azores Sea turtles updated checklist
Sea turtles are the best-known and more widespread marine reptiles. However, information on their distribution and the occurrence of most species, except for nesting beaches, remains scarce and sporadic, depending on sightings from fishing vessels, tourist activities and occurrences in coastal areas as well as fishing bycatch.
Since the last updated species’ list for the Azores (Santos et al, 2010), no new species’ record was known for Azorean waters, until October 2020, with the confirmed sighting of an Olive Ridley, Lepidochelys olivacea (Eschscholtz, 1829) (Barcelos et al. 2021). After that, in February 2021, a second individual was found stranded on Pico Island, already in an advanced state of decomposition. This increased the number of species present in Azores EEZ (Exclusive Economic Zone) to six out of the seven extant worldwide. The remaining one, Natator depressus (Garman, 1880), is native to the Indo-pacific (see Red List Standards & Petitions Subcommittee, 1996).FUNDING: AZORESBIOPORTAL – PORBIOTA (Azores PO 2020 - ACORES-01-0145-FEDER-000072) TOTAL BUDGET: 299. 901,83€ EU Support: 254. 916, 56€ This project was financed by FEDER in 85% and by Azorean Public funds by 15% through Operational Program Azores 2020. This work is also funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT - Portuguese Foundation for Science and Technology under the Research Infrastructure PORBIOTA - Portuguese E-Infrastructure for Information and Research on Biodiversity, project number POCI-01-0145-FEDER-022127.
For the period 2022-2023- Portal da Biodiversidade dos Açores (2022-2023) - PO Azores Project - M1.1.A/INFRAEST CIENT/001/2022.info:eu-repo/semantics/publishedVersio
Non-Linear Relativity in Position Space
We propose two methods for obtaining the dual of non-linear relativity as
previously formulated in momentum space. In the first we allow for the (dual)
position space to acquire a non-linear representation of the Lorentz group
independently of the chosen representation in momentum space. This requires a
non-linear definition for the invariant contraction between momentum and
position spaces. The second approach, instead, respects the linearity of the
invariant contraction. This fully fixes the dual of momentum space and dictates
a set of energy-dependent space-time Lorentz transformations. We discuss a
variety of physical implications that would distinguish these two strategies.
We also show how they point to two rather distinct formulations of theories of
gravity with an invariant energy and/or length scale.Comment: 7 pages, revised versio
Nitrogen compounds prevent H9c2 myoblast oxidative stress-induced mitochondrial dysfunction and cell death
Oxidative stress has been connected to various
forms of cardiovascular diseases. Previously, we have been
investigating the potential of new nitrogen-containing
synthetic compounds using a neuronal cell model and
different oxidative stress conditions in order to elucidate
their potential to ameliorate neurodegenerative diseases.
Here, we intended to extend these initial studies and
investigate the protective role of four of those new synthetic
compounds (FMA4, FMA7, FMA762 and FMA796)
against oxidative damage induced to H9c2 cardiomyoblasts
by tert-butylhydroperoxide (t-BHP). The data indicates that
FMA762 and FMA796 decrease t-BHP-induced cell death,
as measured by both sulforhodamine B assay and nuclear
chromatin condensation evaluation, at non-toxic concentrations.
In addition, the two mentioned compounds inhibit
intracellular signalling mechanisms leading to apoptotic
cell death, namely those mediated by mitochondria, which
was confirmed by their ability to overcome t-BHP-induced
morphological changes in the mitochondrial network, loss
of mitochondrial membrane potential, increased expression
of the pro-apoptotic proteins p53, Bax and AIF and activation
of caspases-3 and -9. Importantly, our results indicate
that the compounds’ ROS scavenging ability plays
a crucial role in the protection profile, as a significant
decrease in t-BHP-induced oxidative stress occurred in
their presence. Data obtained indicates that some of the test
compounds may clearly prove valuable in a clinical context
by diminishing cardiac injury associated to oxidative stress
without any toxicity.Fundação para a Ciência e a Tecnologia (FCT) - Bolsa SFRH/BD/17174/2004, PTDC/QUI/
64358/200
Alvenaria armada : soluções inovadoras em Portugal
Neste trabalho pretende-se abordar aspectos relacionados com as tipologias de paredes de alvenaria estrutural e com a concepção de edifícios em alvenaria. Além disso, são apresentadas duas principais soluções em alvenaria armada que têm vindo a ser objecto de estudo na Universidade do Minho. Discutem-se aspectos de concepção e tipologias e complementarmente os resultados experimentais obtidos na validação experimental de ambas as soluções
Null and timelike circular orbits from equivalent 2D metrics
The motion of particles on spherical 1 + 3 dimensional spacetimes can, under
some assumptions, be described by the curves on a two-dimensional manifold,
the optical and Jacobi manifolds for null and timelike curves, respectively.
In this paper we resort to auxiliary two-dimensional metrics to study circular geodesics of generic static, spherically symmetric, and asymptotically flat
1 + 3 dimensional spacetimes, whose functions are at least C
2
smooth. This
is done by studying the Gaussian curvature of the bidimensional equivalent
manifold as well as the geodesic curvature of circular paths on these. This
study considers both null and timelike circular geodesics. The study of null
geodesics through the optical manifold retrieves the known result of the number of light rings on the spacetime outside a black hole and on spacetimes with
horizonless compact objects. With an equivalent procedure we can formulate a
similar theorem on the number of marginally stable timelike circular orbits of
a given spacetime satisfying the previously mentioned assumptions.publishe
Aqueous biphasic systems in the separation of food colorants
Aqueous biphasic systems (ABS) composed of polypropylene glycol and carbohydrates, two benign substances are proposed to separate two food colorants (E122 and E133). ABS are promising extractive platforms, particularly for biomolecules, due to their aqueous and mild nature (pH and temperature), reduced environmental impact and processing costs. Another major aspect considered, particularly useful in downstream processing, is the "tuning" ability for the extraction and purification of these systems by a proper choice of the ABS components. In this work, our intention is to show the concept of ABS as an alternative and volatile organic solvent-free tool to separate two different biomolecules in a simple way, so simple that teachers can effectively adopt it in their classes to explain the concept of bioseparation processes. Informative documents and general information about the preparation of binodal curves and their use in the partition of biomolecules is available in this work to be used by teachers in their classes. In this sense, the students use different carbohydrates to build ABS, then study the partition of two food color dyes (synthetic origin), thus evaluating their ability on the separation of both food colorants. Through these experiments, the students get acquainted with ABS, learn how to determine solubility curves and perform extraction procedures using colorant food additives, that can also be applied in the extraction of various (bio)molecules.publishe
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